1. Technical Field
The present invention relates to a piezoelectric vibration module.
2. Description of the Related Art
In general, in portable electronic devices, such as a handheld phone, an E-book terminal, a gaming machine, and a PMP, a vibration function is used for various purposes.
In particular, a vibration generation device for generating such a vibration is chiefly mounted on a portable electronic device and used as an alarm function, that is, a silent incoming signal.
In line with the multi-functionality of such a portable electronic device, there is a need for a vibration generation device having a small size, a high degree of integration, and various high functions.
Furthermore, recently, a touch type device for performing input by touching a portable electronic device is commonly adopted according to the demand of users who try to conveniently use portable electronic devices.
A current haptic device includes even a concept on which the intuitive experiences of an interface user are incorporated and feedback to a touch is further diversified in addition to a concept in which input is performed by a touch.
In general, such a haptic device repeatedly expands and/or contracts in response to external power applied to piezoelectric device, thus providing vibration. A vibration generator adopting a piezoelectric device is disclosed in Patent Document 1.
A piezoelectric vibration device disclosed in Patent Document 1 vibrates while generating maximum displacement in both ends up and down using a central portion as a vibration action point or generates vibration by generating maximum displacement in the central portion up and down using both ends as vibration action points in response to a change in the polarity of a voltage applied thereto.
Such a piezoelectric vibration device for generating vibration includes a substrate, a piezoelectric element layer having a piezoelectric material stacked on one surface or both surfaces of the substrate, and an electrode layer for applying a voltage to the top and bottom surfaces of the piezoelectric element layer. As widely known to those skilled in the art, when a signal from the substrate is applied to the piezoelectric element layer, the piezoelectric element layer performs a repetitive vibration movement, and thus it is frequently separated from the piezoelectric vibration device soldered to the end of the substrate.